Tour du Mont Blanc has a shed load of climbing – unless that trip has van uplifts
OP Basque could well be what you are looking for, a different location for most. Good for out of typcail Juky/Aug season too. I follow them on facebook (never been) and am very tempted
Trail Addiction – 2 bases. Around Les Arcs and Dest-X (Areches-Beaufort) – did the latter with them and it was excellent and just as they say, lots of singketrack with hardly any other riders and a planes, trains and automobiles feel to link it all up.
You might look at White Room Chalet also based around Bourg St Maurice valley – I’ve skied with them twice and they are excellent and the riding they put together looks great – its on my list
One last suggestion of you have the budget is Bike Verbier – I’ve never holidayed with them but they are very highly rated and always sell out. I have ridden Verbier 3 times and know I’ve nkt even scratchd the surface of what BV put on in Verbier and beyond.
All of the hokidays involve gtting back to base which imo is no bad thing as you may need to fettle the bike and its good to know you have a comfortable bed and can relax in the surroundings
Get on the facebook pages and websites and have a look
Good luck